Brazil's sports minister resigned on Wednesday after fighting corruption allegations for more than a week, becoming the sixth minister forced to leave office since June, but the government is confident the upheavals will not affect preparations for the 2014 World Cup and 2016 Olympics in the country.

The sports minister, Orlando Silva, maintained his innocence against allegations he took part in a kickback scheme but said he was resigning to avoid prolonging a political crisis for the government.

"I submitted my resignation. I decided to leave the government so that I can defend my honour," Silva said after an hour-long meeting with the president, Dilma Rousseff.

Several people have come forward in the past 12 days to accuse Silva of involvement in kickback schemes linked to projects for social sports programmes. On Tuesday Brazil's Supreme Court said it opened an investigation into the allegations. Silva has already denied the accusations before a congressional panel.

A spokesman for Rousseff's office said no replacement for Silva had been named.

Silva was tasked with overseeing Brazil's preparations for the 2014 World Cup and 2016 Olympics, though his departure is unlikely to affect preparations for those events because responsibilities are spread across many federal ministries, as well as state and city governments.

Silva returned from the Pan American Games in Mexico last week to defend himself against the accusations, which first surfaced in the news magazine Veja, whose reports on corruption have helped lead to the removal of four other ministers since June.

Veja quoted a police officer, João Dias Ferreira, who runs a non-profit sports youth organisation, as saying kickbacks were personally delivered to Silva so that the non-profit organisation could receive government funds.

Silva denies receiving any money from Dias's group and said he believes the allegation was made in retaliation for an investigation he launched into how Dias's group was using government money.

A spokeswoman for Brazil's organising committee had no comment to make. A spokesman for the Olympic organising committee did not return calls, though the group's president, Carlos Nuzman, told the Associated Press last week that the Silva scandal will not affect Rio de Janeiro's preparations for the Olympics.

"Brazil must hold the world record now for the number of ministers forced out because of corruption," said Gil Castello Branco, founder of the non-profit watchdog group Contas Abertas, which campaigns for transparency in government.

He said that Silva's exit was inevitable "but I don't think it will have any effect on the preparations for our two mega-events, the World Cup and the Olympics. Silva is more of a figurehead. The preparations will go ahead without him".

The exit of Rousseff's ministers began in June, when her chief of staff, Antonio Palocci, was forced from his post amid reports about the rapid growth of his personal wealth during his tenure as a legislator, from 2006-2010.

The ministers of agriculture, transport and tourism have also resigned after allegations of irregularities. The defence minister was forced out after publicly criticising other ministers in Rousseff's government.